Kim Jong-nam, North Korean leader Kim Jong-un’s half brother, was assassinated last week by a nerve agent called VX, according to the Malaysian police as reported by the Washington Post. What the heck is VX, and why is it so awful?

VX, or O-ethyl S-(2-diisopropylaminoethyl) methylphosphonothiolate for short, is a colorless liquid nerve agent (not a gas) and a chemical weapon. Drops on the skin can wreak havoc on the nervous system and be enough to kill. VX can poison a person in food and water, or even sprayed as an aerosol—Kim Jong-nam’s assassins wiped it on his face, according to CNN.

Advertisement

The chemical was invented in 1952, by a pair of chemists who discovered it was really good at killing bugs. People soon realized VX would also be good at killing humans. Countries like Russia started synthesizing a slew of other chemically similar “V series” nerve agents, including VR, VE, and so forth. There was a Cold War to fight, after all!

The United Nations listed chemical agents as a class of weapons of mass destruction and banned their development back in 1972, and the Chemical Weapons Convention placed an international moratorium on stockpiling or developing them starting in 1997. Still, it is thought that Iraq used VX while fighting Iran in the 1980s. As of 2013, the United States and Russia were still working on destroying their chemical weapons stockpiles.

The effects of VX are potent: Simply put, it fucks up your body’s chemistry. The body produces a neurotransmitter called acetylcholine that helps cells and nerves communicate with one another. When you’re done with acetylcholine, an enzyme called acetylcholinesterase breaks it down. VX stops acetylcholinesterase from doing its job, so you make far too much acetylcholine, which poisons and kills you. Within a few minutes after exposure to VX, you’ll probably stop breathing, shit yourself, seize and pass out from nervous system overload. The US army killed 6000 sheep in Utah with it in 1968, because why not.

Advertisement

You probably don’t need to worry about VX yourself, because most countries don’t have it, and it requires lots of corrosive chemicals and an expensive lab. It’s so poisonous that the Council on Foreign Relations guesses terrorists wouldn’t even try to handle it, and that those who wanted it would probably opt to steal it from Russian labs. However, CNN reports that it’s not especially difficult to make.

Obviously none of the obstacles, nor any treaty, stopped Kim Jong-nam’s assassins, two women who supposedly wiped the liquid on his face. North Korea denies any involvement, though folks think Kim Jong-un ordered the attack. A 2009 International Crisis group report estimated that North Korea had thousands of chemical weapons, reports CNN. It’s also worth noting that North Korea has not signed the international treaty banning their development.

While in most instances, getting sprayed with VX is a death sentence, in 2004, JAMA released a review about nerve agents which detailed the chemistry and treatment of a few survivors. Those who survived VX exposure had long-term effects like headaches, memory problems and post-traumatic stress disorder type behaviors that lasted months.

Treating VX poisoning requires the immediate administration of a few drugs. First, and most importantly, comes the antidote atropine sulfate to undo the acetylcholine effects. Atropine sulfate is basically administered until the patient starts breathing normally. Other drugs, anticonvulsants called benzodiazepines, are administered to stop the seizing. A third drug, 2-pralidoxime chloride, fixes the acetylcholinesterase so it can keep breaking down acetylcholine.